Safety lock for control levers



Aug. 10, 1926. 1,595,802 w. MERR|LL SAFETY LOCK FOR CONTROL LEVERSFiiged Sept. 14,- 1923 2 Sheets-Sheet 1 l N VENT OR W 7 ATTORNEYS Aug.10, 1926.

. 1,595,802 W. M ERRILL SAFETY LOOK FOR CONTROL LEVERS Filed Sept. 141923 2 Sheets-Sheet 2 INVENTOR BY fl w M ATTOR N 5 VS Patented Aug. 10,1926.

UNITED STATES PATENT OFFICE.

WHITNEY MERRILL, OF BROOKLYN, NEW YORK, ASSIGNOR TO MERRILL BROS., OFMASPETH, NEW YORK, A CORPORATION OF NEW YORK.

SAFETY LOOK FOR CONTROL LEVERS.

Application filed September 14, 1923. Serial No. 662,745.

In machines such as drop hammers for instance, where the foot operatedcontrol lever has a foot pad extending a considerable distance acrossthe machine, there has been constant danger of the premature starting ofthe machine by the unintentional operation of the control lever beingstruck or stepped on. The object of my invention is to prevent thisunintentional operation of the control lever, by providing a manuallyoperated lock which will have to be released before the control levercan be operated, said lock and control lever being preferably located soas to permit their successive operation by a continuous movement in onedirection as, for instance, by a downward movement of the foot whichwill first depress and release the lock lever and then depress andoperate the control lever.

A practical embodiment of my invention is represented in theaccompanying drawings in which the safety lock is shown in connectionwith a drop hammer.

Fig. 1 represents in front elevation so much of a drop hammer as willgive a clear understanding of my invention.

Fig. 2 represents a vertical section from front to rear taken in theplane of the line IIII of Fig. 1.

The base of the drop hammer is denoted by 1. A bar 2 extendshorizontally across the front of the base and is supported in cars 8 and4. The foot operated control lever comprises arms 5 and 6 mounted on thecrossbar 2 and the foot pad or treadle 7 which extends across the frontof the machin-e is secured in the usual manner to the free ends of thearms 5 and 6. This footoperated control lever is connected to the clamprod 8 through the connecting bar 9 and rock lever 10, as-is usual.

The safety lock includes a crossbar 11 carried by the arms 5 and 6 ofthe control lever, on which crossbar 11 is mounted a two armed lever,one arm 12 of which is developed into a hook 13 and the other arm 14 ofwhich is developed into a foot pad located over the foot pad 7 of thecontrol lever.

When the control lever is in its raised or inoperative position, thehook 13 of the lock lever is engaged with an undercut ledge 15 extendinghorizontally across the front of the base 1. A spring 16 extendingbetween the crossbar 2 and a finger 17 on the arm 12 of the lock levertends to return the lock lever to its operative position.

From the above description it will be seen that to operate the controllever, the arm 1% of the lock lever must first be depressed fordisengaging the hooked arm from the undercut ledge 15, when thedepression of the control lever may be accomplished. It will also beseen that the lock and control lever are located so as to permit thesuccessive operation of the two by a continuous movement in onedirection, in the present instance a downward movement.

While I have shown my safety lock in connection with the foot operatedcontrol lever of a drop hammer, it is to be understood that I do notWish to limit myself to this particular application as it is obviousthat the safety lock may he used in connection with manually operatedcontrolled levers of many different devices.

It is evident that various changes may be resorted to in the form,construction and arrangement of the several parts without departing fromthe spirit and scope of my invention; hence, I do not wish to be limitedto the particularembodiment herein shown and described, but- What Iclaim is:

A suitable support having an undercut ledge, a control lever carried bysaid support and a two armed lock lever carried by the control lever,one arm of which lock lever is developed into a hook for engaging saidundercut ledge to lock the control lever in its inoperative position andthe other arm of which lock lever is adapted to be first operated torelease the hook from its engagement with the undercut ledge to permitthe operation of the control lever.

In testimony that I claim the foregoing as my invention, I have signedmy name this 15th day of June, 1923.

